1. Field of the Disclosure
The present disclosure is generally directed to liquid containers and more particularly to an anti-glug device that allows air back into a container to replace lost liquid while pouring liquid from the container.
2. Description of Related Art
Pour spouts that vent (venting spouts), and containers with vents (vented containers) are both known in the art. A typical refillable liquid container of the type that stores liquid and dispenses the liquid from a pour spout has a vent feature or venting capability of some type. The vent is provided to allow air to enter the container as liquid is dispensed in order to replace the lost liquid and equalize pressure in the container. Without such a vent, glugging occurs as a result of return air interrupting the flow of dispensed liquid from the spout. The vent allows the liquid to keep flowing from the container during pouring while return air enters he container via the vent.
More specifically, when liquid flows from a container, a vacuum is created in the vacated interior space in the container. Once the vacuum reaches a certain level, atmospheric air, i.e., return air, is pulled into the container through the dispensing orifice or spout. The return flow of atmospheric air into the container and the flow of liquid from the container utilize the same flow passage or dispensing orifice flow area. The flow of liquid out of the container and the flow of air into the container alternate, depending on the pressure differential in the container. The alternating liquid and air flow causes the glugging action.
In some instances, the vent is provided on the container itself in order to minimize glugging. Such a vent is typically spaced from the dispensing orifice as well as the spout connected to the orifice. The vent on these types of containers typically has its own plug. The plug typically must be manually opened before pouring and then manually closed when done so that liquid does not evaporate from the container during storage. The pour spout also must typically be removed and/or reconfigured when not being used to allow the dispensing orifice to be capped or closed. Also, the dispensing orifice must be capped separately from the vent in order to seal the container for storage and to prevent evaporation. Further, with both the spout and vent opened, if the container is tipped too much during pouring or if the liquid is poured out too quickly, liquid can leak from the vent.
On some containers or products of this type, the pour spout may have a venting feature or vent capability. Some solutions have provided a vent that extends directly through the side of the spout. These types of vents typically leak liquid during the initial pour, at least until air begins to flow back through the vent opening into the container to fill the lost fluid space. Some solutions have provided a vent that extends along the length of the spout. These types of vents typically take a long time to begin allowing return air to reenter the container. This is because the air back flow through the vent passage must first overcome a long column of liquid exiting the vent passage or channel before reaching the container interior. Also, these types of pour spouts typically have a separate air channel and liquid channel along a majority of the spout length. However, the separate channels typically share a single outlet, i.e., an air and liquid passage at the dispensing end of the spout. This can reduce the flow rate of liquid discharged from the spout and can create a significant “glug” effect where air back flow periodically interrupts the liquid flow exiting the dispensing end of the spout.
Other solutions are found on anti-spill pour spouts and other more elaborate systems. Some employ a mechanical shut-off system or valve, which can be costly to manufacture, are likely to be expensive to purchase, and can fail or malfunction during use. Other solutions use a vent that must have a pressure or vacuum differential to open the vent, such as a “duck bill” style valve. A delay typically occurs before the valve opens. Also, the duck bill valve reduces air flow rate through the valve. In containers of relatively heavy wall thickness, the walls do not collapse, which would otherwise aid liquid flow until the valve opens. Also, the size of the valve can limit the flow rate of air back into the container so that the valve cannot keep up with liquid exiting the container.
Large liquid containers, such as five gallon buckets and pails, are provided with separate closures or covers, i.e., lids. The lids are often provided with a pour spout or dispensing orifice to allow controlled pouring of liquid from the container while leaving the lid on the container. These types of containers have similar problems when pouring liquid from the container through the dedicated pour spout or dispensing orifice provided in the lid. Container lids and the spouts for these types of containers were developed in the 1950's. Since their inception, such lids and dispensing spouts have had issues with glugging. Glugging can cause splashing of liquid when pouring from the container. Splashing results in spillage of liquids and spillage results in unnecessary waste and loss of liquid. Depending on the liquid being poured, spillage can also raise environmental concerns and even present a safety hazard. It is nearly impossible to prevent liquid splash caused by glugging, particularly when dispensing a viscous liquid such as motor oil. A common occupational safety hazard is splashing of potentially dangerous chemicals that can harm nearby persons and/or objects. Another common occupational safety hazard is that splashed liquid can contact the eyes of the person pouring the liquid or of other bystanders.
Glugging also can significantly impede pouring or flow accuracy from the container. The intermittent start and stop of liquid flow produced by glugging can cause the flow accuracy to vary widely, such as by six inches or more in some instances. Thus, maintaining pouring accuracy while dispensing from the container into another vessel, such as a funnel, can be quite difficult. These types of containers have often been provided with a separate vent, as noted above, either in the lid or near the top of the container in order to reduce glugging.
Manufacturers of pail and bucket lids have attempted to produce dispensing spouts for the lids that dispense liquids with a continuous liquid flow. However, bucket and pail lid manufacturers have not been successful in producing such a lid. Therefore, the pail lid manufacturers also make and add an additional device to the lid called a back vent that press fits into a hole provided in the pail lid. The end users must open the back vent each time they dispense liquid from the container and then must close the back vent when done to prevent evaporation and contamination of the contained liquid. The back vent allows air into the container, when the vent is open, and thus can reduce the glugging effect.
However, adding the back vent to these types of lids has negative cost and performance implications. Bucket and pail manufacturers must purchase or fabricate the back vents separately and house and store them separately. The manufacturers must also mold or form a separate hole in the pail lid to accommodate the back vent. A production operator must also obtain a back vent for each fabricated lid and then press the back vent into the hole. The increased costs of parts, production, and labor required to make and install a back vent for each lid can add about 20% to the cost of the lid. Such back vents often also will not meet internal container pressure requirements necessary for some hazardous liquids. The internal pressure in a container under a hydrostatic test can cause liquid to leak at the interface between the back vent and the hole in the pail lid. The higher cost and reduced performance of lids with this type of back vent can significantly limit the types of applications and uses for such lids.